The Invisible Sister
by Chucky Ray
Summary: The Doctor is about to find out that his eldest daughter is slowly blossoming into a young woman when suddenly Cassie develops a liquid substance that turns her invisible. Meanwhile The Doctor agrees to babysit Joshua and Susan while Mickey and Martha are out on their honeymoon and chaos erupts! The second part to my Next Doctor series!
1. Chapter 1

Chapter One; Beautiful Memories

Jane sadly sulked inside the house through the front door. "What's wrong with you? Did one of the dinosaurs die or something?" Mickey asked her.

"They're called The Dragons." She corrected him. "And no that's not it." She told him.

"Well then what's the problem?" he asked.

"Uncle Mickey no offense or anything but I really don't want to talk to you about it. Do you know where my dad is?" she asked him.

"Uh yeah he went out shopping, he should be back in a bit though." He told her.

"Well alright, I _suppose_ I can tell you but keep in mind that this is a very private and serious matter." She said.

"Alright, go ahead then, I'm listening." He told her. "What's the problem?"

"Idon'thavebreasts." She mumbled under her breath.

"What?" he asked her with uncertainty.

"I don't have breasts!" she yelled. "You know boobies? Knockers? The big balls that older women carry in the front of their chests? I don't have them!" she shouted catching her uncle off guard.

"Oh, well, you know girls develop them at all different ages." He told her trying to keep a straight face.

"Yeah I know but I'm almost eleven years old and I bet my mother got hers when she was my age." She said.

"Actually I don't think she did. I think she told me that she was about twelve when she started getting them. Now I'm just curious, you don't have to tell me if you don't want to, but what suddenly brought this on?" he asked her.

"Well Maggie just stopped by to play with Peter, and did you see the size of hers? They're huge!" she cried.

"Oh so I see, and now you're jealous of her." He realized.

"No, I'm not jealous of _her_ I'm jealous of her jugs." She said as Mickey stifled a laugh.

"It's not funny!" she yelled.

"Look, I'm sorry but you really shouldn't be so upset about it. I mean didn't your mother always tell you that it's what's on the inside of a person that counts?" he questioned.

"Yeah it's just that, my mother was always so beautiful and sexy and that's why my father fell in love with her. I just really wish that I could be like her someday." She said as she breathed a heavy sad sigh.

"Don't worry, you will." He reassured her. "But your dad fell in love with her for other reasons to." He began.

"Like what?" she asked him when suddenly her father came in through the front door carrying an armful of grocery bags.

"Dad? What made you fall in love with Mum?" she asked him.

"Well gosh, that's an interesting question. What brought this up?" he questioned.

"Well, I'm almost eleven years old and I don't have breasts, and I want to be beautiful and sexy like Mum was." She explained as he gave a little chuckle.

"Oh is that right?" he asked her as he continued to laugh before Jane turned around and ran back down the hallway before slamming her door shut.

 **The Doctor's P.O.V**

"Uh what did I do?" I questioned as I turned to look over at Mickey.

"You laughed at her, you did the one thing that you're not supposed to do!" he exclaimed.

"Well I'm sorry but I thought that it was kind of funny." I told him with another little chuckle.

"Yeah so did I, but I'm her uncle and you're her father. There's a big difference." He told me firmly as my grin immediately faded.

"Oh dear, you don't think I hurt her feelings do you?" I asked him as I took a deep breath and set my bags down on the kitchen counter before I walked down the hall. "Jane," I began as I knocked on the door. "It's me, can I come in and talk to you for a second?" I asked her as I waited for a few minutes until the doorknob turned and the little girl was standing there looking up at me.

"May I help you?" she questioned me before I bent down and picked her up.

"Wow, you really need to cut back on the sweets kid." I told her as I carried her over to the bed and sat her down on my lap. "Look I'm sorry, I didn't mean to laugh at you. You just caught me by surprise, that's all." I explained.

"I just want to be beautiful like my mother was." She told me.

"But darling you are, you are a beautiful and sweet little girl. And you're turning into a beautiful and sweet young woman before my eyes." I said. "So, you wanted to know what made me fall in love with your mother right?" I questioned her as she simply nodded.

"Well it's true that your mother was beautiful both inside and out, but she was also very funny, she made me laugh a _lot_." I told her.

"Do I do that?" she asked me.

"Yeah," I began with a grin before kissing the top of her head. "you do that a lot." I told her. "She was also very smart and brave. That's why I chose her for a companion for the TARDIS because I trusted that she was somebody who could get the job done." I explained when suddenly the grin faded from her face and it turned into a frown.

"I don't think that I could do that." She said with a shake of her head.

"Listen, there's something that I told your sister and now I'm going to tell you." I began. "It's all about faith. I told her that faith was believing in something even when it seems impossible." I told her.

"Yeah but I'll never be as smart as Cassie or as brave as Mum was." She told me.

"You know what? You don't have to be." I said.

"Yes I do, I want my mother to be proud of me." She said.

"Well I think, or rather I actually _know_ for a fact that your mother would be proud of you just for being yourself, because that's all that you really can do." I told her. "And you know what you're more like your mother more than you realize, I see a lot of her in you. You have her heart or hearts as the case may be, and her spirit." I told her with a sniff trying to hold back my tears.

"I love you Dad." She told me as she threw her arms around my neck and hugged me tightly sounding as if she was about to burst into tears herself.

"I love you too." I told her as I hugged her back before brushing away a lone tear that rolled down my cheek.


	2. Chapter 2

Chapter Two; Everybody's Different

 _Ok wow, I'm sorry I'm kind of slow with updating chapters today but I've been busy. Anyway, after that last chapter and listening to Beautiful Memories by The Chipmunks made me tear up. So yeah, sorry for the short delay but here's the next chapter and I hope you enjoy it!_

The next day Mickey and Martha started packing up their things so that they could go on their honeymoon. "Are you sure that you're going to manage everything alright while we're gone?" Mickey asked me.

"Yeah sure, it's only for a couple of weeks. If I need anything Donna told me to get ahold of her. But how much trouble can three children and a few animals be really?" I questioned him back.

"Well alright see you guys later then." He said as he smiled and waved back at us before he walked out through the front door with Martha.

"Alright so," I began as I clapped my hands together. "how about we all go to the park and get some fresh air?" I suggested.

"Alright." Cassie answered.

"I'm good with that." Peter answered with a shrug.

"Me too." Jane responded.

"Good, I'll just go find Shadow and then we'll be all set." I told them before I walked away.

 _…_

"Alright now Shadow let's not say hullo to every tree that we walk past." I told him as I held onto his leash firmly while we walked to the park. He just simply glanced up at me and started to pant when suddenly he stopped as we neared the playground and watched as Jack tried to chase after Joshua while he held baby Susie inside his arms.

"Joshua! Joshua come back here!" he called and as the little boy rounded the corner I quickly handed the leash over to Peter before I scooped him up inside my arms.

"Hey there you little trouble maker you." I said as I quickly adjusted my grip while Jack quickly rushed over to me.

"Thank you Doctor." He told me as he took a deep breath. "I really appreciate it." He said.

"Oh it's alright, I'm used to it. I've been through it three time." I told him. "Where's Sarah?" I asked him.

"Oh didn't I tell you? She's been volunteering at the hospital for the last week and a half. So I've pretty much been mister mum since then." He explained.

"Yeah, I know the feeling. Mickey and Martha just left for their honeymoon." I said.

"Hey Doctor, I realize that it might be asking a lot but I was wondering if you could do me a huge favor?" he began.

"Yeah, sure, anything, you name it." I told him.

"Well you see Joshua's birthday is coming up next month so when Sarah gets home we're going out shopping for him and then we're going out to lunch later. I was just wondering if you'd mind watching the kids." He said.

"Well sure, I'd love to. After all I'm already watching three as it is. What's a couple more?"

"Thanks Doc, I knew that I could count on you." Jack told me.

"You're welcome, here's your kid back." I said as I slowly bent down and set him back onto the ground and watched as he ran off. "Boy I remember back to when Peter was that age." I said before I slowly stood back up again.

"Thanks again Doc, I owe you." He said before he carried Susie away.

"Daddy, can I ask you a question?" Cassie began.

"Well sure munchkin, what's on that enormous mind of yours?" I asked her.

"Why can't Joshua talk?" she asked me.

"Well, he can't talk because he's autistic." I explained.

"What does that mean?" she questioned me as I bent down to her level.

"Well it just means that he has trouble talking because he doesn't know how and he doesn't understand what people say and how to communicate." I explained.

"Oh, will he ever learn to talk?" she asked.

"I dunno," I began with a shrug. "that's something that only time will tell. But it's just like your mummy always told you. We're all different and it would be a boring world if we were all the same." I told her.

"Yeah I remember that she used to say that all the time." She said.

"And it really doesn't matter if we're born boys or girls or autistic or space aliens. Because deep down on the inside we're still just like everyone else." I added.

"Daddy?" she began.

"Yes darling?" I questioned her back.

"Are there kids in Heaven?" she asked me.

"Well yes, I imagine that there probably are." I answered.

"Well then I bet Mummy is doing a really good job of taking care of them up there." She said as I smiled sadly at her.

"Yes sweetheart, she probably is." I told her as I smiled while I watched her turn around and run over towards the playground.


	3. Chapter 3

Chapter Three; The Proper Ingredients

A little while later after we got back from the park it started to rain. After Jack came over and dropped his kids off, Peter took JJ into his room to watch Toy Story while the two girls went back into their bedroom and I put Susie down for her nap. "So what do you want to do now? Play Barbie's?" Jane asked as she flopped down on the bed.

"No, we always do that." Cassie said as she kicked the wall and dangled her head off the foot of the bed. That's when suddenly she shot back up. "I think I'll do a science experiment." She said as Jane just simply groaned at her.

"Cassie! We don't go back to school until another month!" she cried.

"Yeah but then _you'll_ be going to Hogwarts." Her younger sister pointed out.

"Oh yeah that's right, I forgot about that." She said.

"C'mon Jane this is our last chance to do things together before you go away. I remember there are so many things that we wanted to do together with Mummy but we never got the chance." Cassie said.

"Well alright, but first we'll have to go ask Dad if we can use the kitchen." Jane said before the two girls got up and rushed out of the room together. Meanwhile I had had Susie on my lap while I read to her the story of the little engine that could. I kissed the top of her head while she clutched onto her blanket inside her tiny little fingers and sucked on her dummy.

I didn't realize how much I had missed having babies around until that point. That's when suddenly Jane opened the door and both my daughters stuck their heads inside the room. "What is it girls? I'm trying to get Susie down for her nap." I told them.

"We were just wondering if we could use the kitchen for a science experiment." Cassie said.

"Well alright, but just be careful." I told her.

"We will, thanks Dad!" Jane exclaimed before she shut the door tightly behind them and I took a deep breath and sighed before I continued reading the story.

"Alright, so what do you want to make?" Jane asked.

"Something that turns you invisible." Cassie answered.

"What!?" Jane exclaimed when suddenly a huge roll of thunder and a bright flash of lightning lit up of the sky.

"Ah!" Both girls cried as they leaped up into the air.

"It's alright, it's only thunder." Jane said.

"Duh!" Cassie snapped.

"Yeah well you jumped too." Jane pointed out. "Anyway, how are we going to make something that turns us invisible?"

"Well we're aliens aren't we?" Cassie questioned.

"Yeah, so?" Jane questioned her back.

"So, we'll just use Daddy's special ingredients out of the cupboard." Cassie told her before she pushed the stepstool over to the kitchen counter and climbed on top of it before she opened it up. "Now let's see, we'll need just a little bit of frog's breath since that will create the foggy mist," she began as she took the vile out of the cupboard and sat it down on the countertop.

"About a half cup of flour to turn us white mixed with water to make us transparent," she continued as she set the bag of flour down next to the frog's breath. "And of course some apple juice just to make it taste better." She said before she shut the cupboards and leaped back down on the ground.

"Uh Cassie, I changed my mind. You go ahead." Jane said.

"Why? Don't you want to become invisible so that we can pull pranks on Daddy and Peter?" she questioned her.

"No, not really. I mean if we became invisible there's no guarantee that we would become visible again. I'm going back to my room and going on the computer. Have fun but don't make a mess." She told her before she turned and walked back down the hallway.

"Well alright, suit yourself." Cassie said with a shrug as she opened the refrigerator and got out the whole container of apple juice and set it up on the counter before she began to pour and mix all of the ingredients inside of it.


	4. Chapter 4

Chapter Four; The Invisible Sister

"Hey munchkin whatcha doing?" I asked her as I quietly shut my bedroom door behind me and walked out into the kitchen.

"Oh, I was just drinking some apple juice." She answered quickly before shoving the container back in the fridge.

"What happened to Jane?" I asked her.

"She's on the computer." She told me.

"Oh I see and the boys are watching a movie and I just put Susie down for her nap. Well I guess that means that we have some free time on our hands. What do you want to do?" I asked her.

"Can we give makeovers and have a tea party?" she asked me eagerly.

"How about I make _you_ over and then we can have a tea party." I suggested.

"Yay! With the curler and everything!?" she exclaimed.

"Sure, but please don't be mad at me if it isn't completely perfect." I told her.

"Alright, deal!" she cried before she ran back into the bathroom.

.. _…_

A little bit later Jane walked out of her bedroom to find Cassie's hair all covered in curls and her nails being painted a bright red. "Hey! No fair!" she yelled.

"Hey don't get mad at Cassie, you're the one decided that you didn't want to play with her anymore." I told her.

"I'm sorry," she began. "can you do me next?" she asked me hopefully.

"Sure, just as soon as I'm finished painting her nails." I answered with a grin.

"Alright," she began. "boy I'm thirsty, I think I'll get something to drink while I'm waiting." She said as she walked into the kitchen and opened the fridge and Cassie gave a sudden loud gasp before she quickly turned her head as she watched as her sister removed the container of apple juice from the fridge and got out a glass to pour it in.

"Jane no!" she cried. "Don't drink that!" she exclaimed.

"Why not?" Jane asked her while she poured the substance inside her glass before bringing it to her lips to drink it.

"No! Don't!" Cassie yelled when I suddenly stopped painting her nails.

"Cassie what's wrong? What's the matter?" I asked her but before she could answer me it was too late. Jane started to gulp the substance down into her throat and as she did so she slowly disappeared.

"Oh my God." I said as my eyes widened with astonishment as I watched my daughter vanish.

"What's going on? What happened?" Jane asked as we watched the empty glass magically set itself back down on the counter.

"You're invisible." Cassie told her with a sudden gasp of disbelief.

"I'm what!?" she cried as she ran down the hallway and we suddenly felt a breeze of the invisible force running past us before it turned the corner and ran inside the bedroom.

Jane let out a horrified shriek as she caught sight of herself inside the mirror.

"Cassie, what did you do? Why is Jane invisible?" I questioned her as she took a deep breath and sighed.

"She's invisible because she drank my potion." She began. "I made one with the ingredients that I found inside the cupboard." She explained.

"Well sweetheart you should have told me." I told her.

"I know Daddy, I'm sorry." She apologized.

"So that means that you lied to me before when I asked you what you were doing in the kitchen." I realized.

"I know, I'm sorry." She told me again.

"Well, I accept your apology but I want you to go to your room for a little while and think about what you did." I told her.

"Yes Daddy." She said before she got up and walked down the hallway and into her room before Jane ran back out of the bathroom.

"What am I supposed to do about this!?" she yelled.

"Alright Jane just hold on. Donna told me to call her if there were any problems. I'm sure between the two of us we can find a way to make you visible again." I told her before I dug out my cellphone and started dialing her number.


	5. Chapter 5

Chapter Five; Cassie's Lullaby

 _Alright, so I just HAD to put the song that I was listening to earlier into this story because it fits the whole situation so much. Just to let you know that this is the last chapter and it gets a little emotional at the end. I'll put the next one up tomorrow which is going to be entitled The Resurrection Ring which means, Rose is going to be in it, YAY! Alright please enjoy the rest of the story and PLEASE review, review, review! I want to know what things I'm doing great on and the things that I could improve on, so please give me some feedback people and thank you for reading!_

A little while later the doorbell rang and I went to go answer it to find Donna standing on the other side of it. "This better be important, I was just in my Jacuzzi tub." She said as I took her by the arm and dragged her inside the room before closing the door behind her.

"It is, Jane's gone." I responded.

"Again!? I thought she would have learned her lesson by now and that she would stop running off by now." She said.

"No I'm sorry you misunderstood me, she's still here. She's just not _here_." I told her.

"Alright c'mon then what are you on about? Spit it out then!" she exclaimed.

"He means that I turned invisible." Jane said when suddenly Donna gave a shriek.

"Oi! Who said that!?" she exclaimed as I heaved a small sigh and dug a par of cardboard glasses out of my pocket before I placed them on her face. Donna gave another petrified shriek when suddenly Jane came into view. "Oi! Where did you come from!?" she cried.

"I accidentally drank a potion that Cassie made that turned me invisible." She explained.

"Yeah and now we just need the antidote." I told her before I removed the glasses from her face.

"Oh really and how am I supposed to know it!? And what the hell are these anyway!?" she exclaimed.

"They're special glasses that have the ability to see through certain things or rather things that aren't there." I told her.

"So what they're like X-ray glasses?" she questioned me when suddenly Peter and Joshua came out of their room.

"What's going on here? Where's Jane?" Peter asked.

"Your sister accidentally made her disappear and so now Donna is going to help watch you while Cassie and I come up with the antidote. You wouldn't happen to know it would you?" I asked him.

"Actually, I think I read it inside a book once." He said when suddenly the power went out.

"Oh that's just great! Now we're sunk!" I shouted as I threw my hands up into the air and Cassie ran out of her room.

"Daddy! I'm scared!" she cried as she jumped into my arms.

"It's alright darling, we'll get some flashlights out of the closet." I told her as she hid her face inside my chest and started to tremble and shake with fright.

"I don't like the dark." She said anxiously.

"Shh,.." it's alright I whispered as I gently kissed the top of her head and rubbed her back soothingly.

"Now it'll be impossible for anyone to see me!" Jane cried.

"Maybe not," Peter began before he started to walk back down the hallway and removed his sonic screwdriver from his pocket before he pressed the button and turned it on.

"Peter? Where are you going?" Jane asked as she ran after him.

"Over to my bookshelf. Since I'm the next time lord I have a lot of them and I've had to read a lot of things about stuff like this." He told her as he pointed the tip of the sonic screwdriver at all the different kinds of books before he stopped and pulled one out. "Aha! This one should have it. Common pranks that aliens and other supernatural beings pull." He said as he set the book on top of his desk and shone the light down at it.

He continued turning pages for a while until he finally stopped on the proper page that had the antidote. "Here it is, the antidote to the invisibility potion is believe it or not love and happy memories." He read.

"What!? What kind of antidote is that!?" Jane exclaimed.

"I dunno, that's just what it says." He told her.

"But how can a potion have that?" she asked him as he closed the book again.

"Well, maybe it's not supposed to be a potion." He told her.

"You mean if we all get together and start telling stories about Mum, I will become visible again?" she questioned.

"I'm not sure, but it's worth a try." He told her before they both came back out of the room.

"So, did you find the antidote?" I asked them.

"Peter thinks if we start telling stories about how much fun we had with Mum and how much we loved her that I won't be invisible anymore." Jane said.

"Well, alright. I've got the flashlights so we'll just sit down right here and talk about it." I said as I set a flashlight down in the center of the floor and turned it on. "Oh my gosh where do I start?" I wondered.

"I know, what if we go around the circle and each share a happy memory about her. Except for JJ of course, he can just listen." Cassie suggested.

"That is an excellent idea Cassie. I'll start." I began. "Well one of my favorite memories was when Cassie was a baby and we all went to the zoo together. Your mother loved looking at all the different kinds of animals, especially the monkeys. I think it was because she was one." I said as everyone else laughed and then it was Donna's turn.

"Well my favorite memory is when I first met you and Rose, I didn't have a clue what I was doing or why I just suddenly showed up inside the TARDIS but Rose was so sweet and understanding about it that it's no wonder why we became fast friends. I sort of think that I became like a mother figure to her, and she certainly was like a daughter to me, I loved her so much. And I always will." She said with a nod and a sniff. "Sorry," she apologized before brushing away her tears.

"Don't worry Donna it's alright, Peter, what about you?" I asked him.

"Well my favorite memory of my mum is when she saved up all her money to give me that shiny red bicycle that I wanted when I was Joshua's age and taught me how to ride it. Of course she taught me so well that a couple years later Dad was able to show me how to ride it without training wheels." He said.

"Yeah that's a good memory," I began before I placed the special glasses onto my face and looked over at Jane and looked at her. "Jane, what's your favorite memory about your mother?" I questioned.

"Well, I always loved it when she used to sing to me before bed to help me get to sleep." She answered.

"Oh yeah, there was that song that she always used to sing but I forgot the name of it." Cassie said.

"I remember it." Peter began before he started to sing it softly.

Content deleted they sing beautiful memories by the chipmunks


End file.
